Foldable lock for sofa beds



Mardl 1961 R. COOPERSMITH ETAL 2,975,433

FOLDABLE LOCK FOR SOFA BEDS 4 Sheets-Sheet 1 Filed July 21. 1958 ma m isw WIN 2 N Z a E w 6 d /Wr/M mmw Wm FMJ March 1961 R. COOPERSMITH ETAL2,975,433

FOLDABLE LOCK FOR SOFA BEDS Filed July 21, 1958 4 Sheets-Sheet 2 Fara Pb[wa ts/1v MM #0154 1014 /VA M5 flaw/V5447? March 21, 1961 R. COOPERSMITHETAL 2,975,433

FOLDABLE LOCK FOR SOFA BEDS Filed July 21. 1958 4 Sheets-Sheet 3 I V FIG6 22 as" J a 6 LBK ZEQQEQ .55

MQ /W March 21, 1961 R. COOPERSMITH ETAL 2,975,433

FOLDABLE LOCK FOR SOFA BEDS Filed July 21, 1958 4 Sheets-Sheet 4 6/19Famu/MwPa sw/m 3 7 May/n54 402mm 35 5 Im/us 62551134077 Unite States2,975,433 FOLDABLE LOCK FOR SOFA Bans Filed July 21, 1958, Ser. No.750,002 6 Claims. on. -55

This invention relates to improvements in furniture of the. sofa bedtype in which a foldable bed frame mechanism is operatively mounted in asofa frame to fold outwardly when used as a bed and to fold inwardly ina compact manner to form the seat when used as a sofa.

. Sofa bed constructions of the typeexemplified herein usually employ aninner spring mattress to provide sleeping comfort. The bed framemechanism, therefore, is constructed to enfold the mattress in a compactmanner to obviate its removal when the furniture is to be used as asofa. It has been a problem to hold the bed frame mechanism in itsfolded condition against the spring-back action of the mattress springcoils during this inward folding of the bed frame mechanism to form thesofa seat. If the bed frame mechanism is not held in its folded positionthe moving parts of the assembly will interfere with the stationaryparts. The bed frame then cannot be smoothly passed back of the sofa toform the sofa seat. Anumber of arrangements of bed frame mechanism havebeen advocated to surmount this problem, but none has been foundcompletely satisfactory.

An object of this invention, therefore, is to provide a foldable bedframe mechanism which will overcome this difi'iculty in a novel mannerby employing a simple arrangement of parts to exert a mattresscompacting force sufficient to overcome the spring-back action of themattress spring coils.

More specifically it is an object of this invention to incorporate in afoldable bed frame mechanism a pulldown lever system operably connectedto parts of the bed frame so as to exert a powerful force on themattress to retain the same in compact folded condition.

It is a further object of the invention to provide a foldable bed framelocking system in which a simple swing-over lever is at times free tomove about a pivot and at other times is held against swinging motion bya pull-down lever connected to the swing-over lever at a point spacedfrom the pivot, thereby locking the swingover lever against freemovement.

Other objects of this invention reside in the means and mechanismhereinafter to be described in connection with a presently preferredembodiment of the invention.

In the embodiment chosen for detailed description the improvementsconsist in a pull-down lever system for the opposite sides of thefoldable bed frame mechanism. Each system includes a cam-type swing-overlever formed with an elongated slot to provide a shsiftable contactbetween the swing-over lever and a pull-down member so that at times thecontact of swing-over lever and pull-down member may be brought togetheradjacent apivot and at other times may be moved apart to form spacedpoints of engagement. The invention also consists in the parts andmechanisms of the embodiment disclosed herein and set forth in theclaims which form a part of the specification.

In the drawings:

Fig. 1 is a side elevational view of the sofa bed as- 2,975,433"Patented Mar. '21, 1961 sembly showing the foldable bed frame mechanismextended in bed forming position;

Fig. 2 is a plan view of the sofa bed seen at line 22 in Fig. 1;

Fig. 3 is a sectional elevational view of the assembly of Fig. 1 withthe bed frame mechanism in partly folded position;

Fig. 4 is a view similar to Fig. 3, but showing the folding action in amore advanced condition;

Fig. 5 is a view similar to Fig. 1, but showing the folding actionthereof in a still more advanced condition;

Fig. 6 is a view similar to Fig. 1 but with the bed frame mechanismfully folded;

Fig. 7 is an enlarged fragmentary View of the pulldown lever system forlocking the foldable bed frame mechanism Fig. 8 is a transversesectional view seen at line 8-8 in Fig. 7;

Fig. 9 is a view similar to Fig. 1, but showing the mattress in positionof being folded by the bed frame link- Fig. 10 is a view like Fig. 9,but showing the folding operation more advanced; and

Fig. 3.

Fig. 11 is a further view of the folding action of the linkage. V

In Figs. 1 and 2, the furniture assembly is seen to include a sofa frame1 and a foldable bed frame mechanism 2 connected to the frame in asuitable manner. The frame includes side arms 3, a back 4, a base 5 andlegs 6. The bed frame mechanism 2 includes mounting means 7 connected tothe base 5, fold control links 8 pivotally connected to the back 4 andlinks 9 pivotally connected to the fold control links 8 to guide theframe mechanism during folding and unfolding.

The bed frame mechanism 2 comprises four foldable frame sections whichare conveniently designated as the head section A, an intermediatesection B, a front section C, and a foot section D. Each of thesesections is understood to include spaced side members 11, 12, 13 and 14respectively (Fig. 1) formed of suitable structural angles or barsconnected by transverse members 15, 16, 17 and 18. Head section A ispivotally connected at its corners to the frame 1 by the control links8, as shown in Fig. l, and is also pivotally connected to intermediatesection B at pivots 19. In turn, section B is pivoted to section C atpivots 20, and section C is pivoted to section D at pivots 21. Thefolding action of the mechanism 2 is carried out by raising section Drelative to section C to a right angular position, as in Sections D andC may then be folded relative to section B until the position of Fig. 4is reached, then sections D, C, and B fold together relative to sectionA and the frame 2, as in Fig. 5. The whole mechanism may then be swunginto frame 1 to complete the folding action, as shown in Fig. 6. Thusthe foot section D folds to final position over section B and issubstantially parallel and spaced thereabove by the lengthof section Cso that a space is provided to enfold the mattress M. Section C carriesan upholstery board 22 which is attached to the side members 13 bybrackets 23 and which assumes a position at the front of frame lwhen themechanism 2 is supported at its foot section by legs 24 pivoted at 25 tothe side members 14. The legs 24 are caused to fold inwardly adjacentmembers 14 by links 26. These links 26 are connected at 27 to the legs24 and connected to the side members 13 ofsection C by pivots 28.Intermediate legs 29 which are pivotally carried on brackets 30 of theside members 12 of section B support the adjacent sections B and C.Links 31 cause these legs 29 to fold inwardly adjacent side members 12during conversion of the bed to the sofa seat position of Fig. 6.Section B is also supported in the frame 2by fold control links 32 whichare pivoted at 33 to the mounting means 7. The links 32 are pivoted todog-leg type suspension levers 34 at point 35. The suspension levers 34,are connected to the side members 12 of section B at point 36 and havedepending arms 37. The lower ends of the arms 37 are engaged by links 31at pivots 38. Counter-balancing springs 39 are connected to the mountingmeans 7 and to idler links 40. The idler links 40, in turn, areconnected at pivots 41 to the fold control links 32, to the side members11 of section A at pivots 42 and tolinks 9 at pivots 43.

The pull-down lever system (Figs. 1, 7 and 8) incorporated in .thepresent foldable bed frame mechanism includes similar means at each sideof the bed frame. Therefore, only one such system will be described indetail. The system is seen to include a cam type swingover lever 45having a pivot at one end connecting the swing-over lever 45 to the sidemember 12 of section B. The opposite. end of the swing-over lever 45 hasa pivot 47 connecting it to a link 48. The link 48 is pivotallyconnectedat pin 49 to the side member 14 f section D outwardly of thepivot 21. The swing-over lever 45 is also formed with a cam slot, oneportion 50 of which is spaced from and concentric with pivot 46 as acenter, and another portion 51 isdirected lengthwise and at apredetermined angle relative to a straight line connecting the pivots 46and 47. The pivot 46 is formed with an elongated stud 52 having a head53. This is best seen in Fig. 8. A pull-down member 54 having an angularprojecting tang portion 55 on one end is fastened at the other end topivot 38. The end having the tang portion 55 is provided with a pin 56located adjacent said tang portion 55. The pin 56 may run in the slotportions 50 and 51, and thus connects the pull-down member 54 to theswing-over lever 45. The tang portion 55 is adapted to be receivedagainst the elongated stud 52, as will be explained later.

The swing-over lever 45 is shown in Fig. 7 in the position assumed whenthe bed frame mechanism 2 is extended to the bed forming position ofFig. 1. As the mechanism 2 is folded into sofa frame 1 to make up asofa, the swing-over lever 45 swings about pivot 46 in acounterclockwise direction through the several positions shownsuccessively in Figs. 3 and 4. During this counterclockwise motion ofthe swing-over lever 45 shown in Figs. 1, 3 and 4, the pull-down member54 remains relatively stationary so that the concentric or arcuate slotportion 50 moves entirely past pin 56, and a part of the slot portion 51may also run past the pin 56. This puts the tang 55 of the pull-downlever 54 in position to be received against the elongated stud 52. Thus,there is no mechanical interference between the swingover lever 45 andthe pin 56 of the pull-down member 54, and the folding action of framesections D, C and B is accomplished without hinderance.

A gravity latch H having a latch pin engaging recess 57 is pivotallyattached at 58 to the leg 24. The latch H is adapted to engage a stud 59when the bed is in the position of fold shown in Fig. 4. When the stud59 is engaged by the latch H, sections D and C are locked together. Asthe mattress M is compressed during the folding operation itsspring-back force besides exerting a force tending to unfold sections B,C and D also tends to make section D move in a direction of shear withrespect to section B. .This shearing tendency increases as the partsbecome worn. By thus locking the leg 24 to the link 26 by the gravitylatch. H and the stud 59, this shearing tendency is defeated and thefurther folding operation shown in Figs. and 6 can be accomplished.

The folding action of the mechanism 2 from the position of Fig. 4 to thepositions of Figs. 5 and 6 successively is carried out by lifting andpushing inwardly on front section C. This action causes relativemovement between section B and the fold control links 32 about pivots 33so that suspension levers 34 experience motion in a clockwise senseabout the pivots 36 of the side members .12 of section B. The lower arms37 of the suspension levers 34 thereby exert apullingforcesimultaneously upon links 31 to fold legs 29 and upon pulldown members54 to cause the pins 56 to run out into the slot portions 51 ofswing-over levers 45. Figs. 4, 5 and 6 show the operation without themattress in the frame. However, as the front section C is lifted withthe mattress inposition, as in Figs. 9, 10 and 11 there is a criticalperiod when the mattress spring-back force tends to force the sections Dand 'C upwardly of the folded position shown in Fig. 9. The action ofthe tang 55 against the elongated stud 52 and of the pin 56 against theslot portion 51 is adapted to resist the mattress spring-back force.This spring-back force is exerted through link 48 and pivot 47 to theswingover lever 45 tending to rotate it in a clockwise direction. Thiscauses the arcuate slot portion 50 to run past the pin 56. However, thetang 55 reacting against the elongated stud'52 resists the tendency ofthe slot portions 50 and 51 to move past the pin 56. Therefore, theswing-over bar 45 cannot rotate in a clockwise direction and thesections D, C and B are held in a folded position until the furtherlifting of section C has forced the slot-portion 51 past the pin in acounterclockwise direction locking the sections securely together. Ifsections D, C and B are allowed to spring apart from the folded positionshown in Fig. 4 they Will not fit into the frame 1.

During the folding action the pins 56 run out farther into the slotportions 51 and a pull-down force is exerted on the swing-over levers45. The size of this pull-down force is governed by the angle ofinclination of the slot portion 51, as previously defined. This run-outof pins 56 in slot portion 51 transmits the resulting pull-down force orload through the swing-over levers 45 to link 48 which is connected tofoot section D, thereby causing the section D to draw down upon themattress M and oppose the mattress spring-back tendency. The simplemechanical motion' of the parts described produces a powerful lockingload on section D and allows the mechanism to pass unobstructedlybeneath the back cushion of the sofa. Thus, the desired result issmoothly and forcefully obtained by creating at the proper position ofthe folding action (Fig. 5) three points of connection at the swing-overlever 45. The intermediate point of connection at pin 56 is then guidedalong the slot portion 51 to a zone between end connections 46 and 47. Alocking load is here exerted through swing-over lever 45 and link 48upon the frame section D which now (Fig. 6) forms the seat section ofthe sofa.

The advantages of the foregoing improvements and the economies .of itsmanufacture and operation will be appreciated from the detaileddescription. However, certain modifications and substitutions ofequivalent parts for those herein described may appear afterunderstanding the principles of the invention, and all suchmodifications and substitutions of equivalent parts are intended to beincluded within the spirit and scope of the annexed claims.

What is claimed is:

*1. In combination with an articulated bed frame having first, secondand third relatively rotatable sections adapted to move between anextended bed defining position and a seat supporting position in a sofaframe of which the first section and the third section are foldable intoa substantially parallel relationship; an elongated swingover memberhaving one end pivotally attached to the third section and provided witha slot having a substantially arcuate portion opening into asubstantially straight portion which extends substantially lengthwise ofa a said swing-over member at a predetermined angle relative to thelongitudinal; axis of said swing-over member; means linking the otherend of said swing-over member to the first section, said swing-overmember being pivotally responsive to movement of the first section; anelongated stud projecting from said pivot; a pull-down mem her having apin fastened thereto, said pin being movable in said slot of saidswing-over member; link means connecting said pull down member at oneend thereof to the third section; a tang carried by said pull-downmember and extending from the other end thereof at a 4 predeterminedangle, said tang engaging said elongated stud when the first section ismoved toward a position substantially parallel to the third section.

2. In combination with an articulated bed frame having first, second andthird relatively foldable sections adapted to be moved between anextended bed defining position and a seat supporting position in a sofaframe of which the first section and the third section are foldable intoa substantially superposed relationship; a swing-over member pivotallyconnected to the third section and provided with a slot having anarcuate portion substantially concentric with said pivot and asubstantially straight portion joining said arcuate portion at apredetermined angle; link means connecting said swing-over member to thefirst section, said swing-over member being rotated about the pivot whenthe first section is moved in a counterclockwise direction about thesecond section; an elongated stud projecting from said pivot; apull-down member; link means connecting said pull-down member to thethird section; a tang carried by said pull-down member and extending ata predetermined angle from one end thereof; and means connecting saidswing-over member and said pull-down member, said connecting means beingmovable in said slot portions of said swingover member and connected tosaid pull-down member at a point adjacent said tang, said tang abuttingsaid elongated stud when the first section is moved toward a positionsubstantially superposed relative to the third section.

3. A locking mechanism for a sofa bed construction having a plurality ofarticulated bed sections of which a first section and a third sectionare interconnected by a second section and are foldable into asubstantially superposed relationship and in which the third section ismovably connected to a fourth section; said locking mechanism comprisinga swing-over member pivoted at one end to the third section and formedwith a slot having an arcuate portion adjacent said pivot and anelongated portion joined to the arcuate portion and extending substantially lengthwise of said swing-over member; link means connectingthe other end of said swing-over member to the first bed section, saidswing-over member being pivotally responsive to movement of the firstbed section; a pull-down member; link means connecting one end of saidpull-down member to the third bed section; and connecting meansconnecting the other end of said pull-down member with said swing-overmember, said connecting means being received in and movable in the slotportions of said swing-over member, said pull-down member beingsubstantially stationary when the first bed section is moved to asuperposed folded position relative to the third bed section; saidpull-down member moving the connecting means into the elongated portionof the slot when the folded first, second and third bed sections aremoved relative to the fourth sec-tion thereby locking the first andthird bed sections in a folded relationship.

4. A locking mechanism for a sofa bed construction having a plurality ofarticulated bed sections movable from a bed defining position to a sofaseat supporting position of which a first section and a third sectionare interconnected by a second section and are foldable into asubstantially superposed relationship; said locking mechanism comprisinga swing-over member pivoted at one end to the third section and formedwith a slot have ing an arcuate portion and an elongated portion joinedto said arcuate portion and extending toward the other end of saidswing-over member; an elongated stud extending from said pivot; linkmeans connecting the other end of said swing-over member to the firstsection, said swing-over member being pivotally responsive to rotativemovement of the first section about the second section and arranged tolie substantially adjacent the third section with said elongated slotportion disposed above said pivot when the bed sections are in a beddefining position and arranged to lie substantially adjacent the thirdbed section with said elongated slot portion disposed below said pivotwhen the first bed section is moved to a position substantiallysuperposed relative to the third bed section; a pull-down member; a tangcarried by said pull-down member and extending at a predetermined anglefrom one end thereof; link means fastened to the a other end of saidpull-down member linking said pulldown member to the third bed section,said pull-down member being substantially stationary when the first bedsection is moved to a position substantially superposed relative to thethird bed section; a pin carried by said pull-down member adjacent saidtang operatively connecting said pull-down member to the slot of saidswingover member, said pin being slidable in said slot portions of saidswing-over member, said arcuate slot portion moving past said pin in acounterclockwise direction when the first bed section is moved to aposition substantially superposed relative to the third bed section,said tang engaging said elongated stud when the first bed section ismoved toward a position sub-stantially superposed relative to the thirdbed section.

5. A locking mechanism for a sofa bed construction including a sofaframe having a plurality of articulated bed sections movable from a beddefining position to a sofa supporting position of which a first sectionand a third section are interconnected by a second section and arefoldable into a substantially superposed relationship and in which thethird section is movably connected to a fourth section; said lockingmechanism comprising a swing-over member pivoted at one end to saidthird section and formed with a slot having an arcuate portionsubstantially concentric with said pivot and an elongated portion joinedto said arcuate portion and extending toward the other end of saidswing-over member; an elongated stud extending from said pivot; meanslinking the other end of said swing-over member to the first section,said swing-over member being rotated about the pivot when the firstsection is rotated about the second section and arranged to liesubstantially adjacent the third section with said elongated slotportion disposed above said pivot when the sofa bed construction is in abed defining position and arranged to lie substantially adjacent thethird section with said elongated slot portion disposed below said pivotwhen the first section is folded to a position substantially superposedrelative to the third section; a pull-down member; a tang carried bysaid pull-down member extending from one end thereof at a predeterminedangle; link means located near the other end of said pull-down memberlinking said pulldown member to the third section, said linking meansbeing pivoted to the third section; means pivotally connecting saidsecond mentioned linking means to the sofa frame; and a pin connectingsaid swing-over member and said pull-down member, said pin being movablein said slot portions of said swing-over member and fastened to saidpull-down member at a point adjacent said tang, said tang abutting saidelongated stud when the first bed section is moved toward a foldedposition substantially superposed relative to the third bed section,said pulldown member being substantially stationary while the firstsection is moved to said folded position, said pin moving in saidarcuate portion of said slot during said folding operation, saidpull-down member moving said aeraass,

pin in said elongated portion of said slot when the folded first, secondand third bed sections are moved relative to the fourth bed section.

6. A locking mechanism for a sofa bed construction having a plurality ofaiticulated bed sections of which a first section and a third sectionare interconnected by a second section and are foldable into asubstantially superposed relationship and in which the third section ismovably connected to a fourth section; said locking mechanism comprisinga swing-over member pivoted atone end to the third section and formedwith a slot having an arcuate portion substantially concentric with saidpivot and a substantially straight portion joined to the arcuate portionat a predetermined angle; link means connecting the other end of saidswing-over member to the first bed section, said swing-over member beingvpivotally responsive to movement of the first bed section; a pull-downmember; link means connecting one end of said pulldown member to thethird bed section; and connecting means connecting the other end of saidpull-down memher with said swing-over member, said connecting meansbeing received in and movable in the slot portions of said swing-overmember, said pull-down member being substantially stationary when thefirst bed section is moved to a superposed folded position relative tothe third bed section; said pull-down member moving said connectingmeans into the straight portion of the slot when the folded first,second and third bed sections are moved relative to the fourthsection'thereby locking the first and third bed sections in a foldedrelationship.

References Cited in the file of this patent UNITED STATES PATENTS2,721,337 Bank et al. Oct. 25, 1955 2,770,814 Schindler Nov. 20; 19562,785,415 Peterson Mar. 19, 1957 2,829,382 Bank at al. Apr. 8, 19582,844,827 Bank et al. July 29, 1958

